There can be various types of filters in a data storage systems, such as hard disk drives (HDD), at any one time. For example, recirculation filters may be found in the path of airflow caused by the spinning motion of the media. Such recirculation filters are designed to filter out particles which become airborne during the operation of the drive. Breather filters are located on the cover or base casting and are designed to allow for pressure equalization in the drive, without the introduction of particulate contamination. Another type of filter is an organic adsorption filter which is used to reduce organic vapors or reactive gases that might enter the drive or condense on the media or sliders within the drive. There are also desiccant containing filters to lower the relative humidity within the data storage system.
Data storage system, including HDDs, are increasingly being manufactured with smaller form factors and increased storage capacities. This fact places an even greater premium on space within the HDD. Critical components of an HDD requiring such space include the aforementioned recirculation and adsorption filters. Recirculation filters are a particularly important component of the HDD since particulate matter on disk's surface can significantly interfere with the operation of the HDD's read/write head. As the disk spins, airflow tends to move particles between the read/write head and the disk surface, thereby resulting in possible component damage or read/write errors.
Given the space constraints within the HDD, it has become increasingly necessary to produce a recirculation and/or adsorption filter having a very small form factor. In addition, the now-higher storage capacities of HDDs require higher filtration efficiencies since even the smallest particles can disrupt the HDD's operation. Finally, there is a constant need to minimize cost and maintain ease of assembly for all HDD components. Thus, there is a need for an improved HDD recirculation filter which satisfies one or more of the aforementioned needs.